This disclosure relates to an image forming apparatus such as a copier, a printer, a facsimile, or a multifunction peripheral, and more specifically to a technology for grounding a unit detachably fitted to a main body of the image forming apparatus.
The image forming apparatus is composed of various components and units in combination, and some of these components and units are required to be connected to a grounding portion of a main body of the image forming apparatus.
For example, in the image forming apparatus, a paper feed cassette loading and storing recording paper is provided, and from this paper feed cassette, the recording paper is withdrawn and then supplied, and an image is formed on this recording paper. In such an image forming apparatus, grounding is provided for removing unnecessary electrical charges. For example, such unnecessary electrical charges are generated in a main body of the apparatus. Moreover, upon the supply of the recording paper, between the withdrawn paper and the recording paper left on the paper feed cassette, friction is generated which causes, on the recording paper, electrical charges, which flow from the recording paper to the paper feed cassette. If these electrical charges are accumulated in the paper feed cassette and then discharged, noise is generated, which has an influence on an image forming process and deteriorates image quality. Thus, the paper feed cassette is connected to a grounding portion of the main body of the image forming apparatus to make the electrical charges in the paper feed cassette flow to the grounding portion of the main body.
Moreover, suggested is a conductive mechanism which includes: a coil spring pushing up a paper loading board of the paper feed cassette; a coil spring having an extended part connected to the aforementioned coil spring; a lock board, etc. and which makes electrical charges in the paper loading board flow to a paper feed section frame on a main body side of the image forming apparatus via the coil spring, the extended part, the coil spring, and the lock board.
Further, there is a conductive mechanism which has a grounding spring provided at a bottom surface of the paper feed cassette and which, with the paper feed cassette inserted and set in a housing of the main body of a printer, makes the grounding spring in contact with a metallic plate in the housing of the main body to make electrical charges in the paper feed cassette flow to the plate in the housing of the main body via the grounding spring.